树舌胞外多糖提取条件优化

对树舌发酵液中胞外多糖的提取工艺进行研究,考察发酵液浓缩比例、乙醇终浓度、pH对胞外多糖提取量的影响.在单因素试验的基础上,进行了正交优化试验,确定了树舌胞外多糖的最佳提取工艺条件为：发酵液浓缩比例为1/2、乙醇浓度为80％、pH 7.0,此条件下树舌胞外多糖提取量为0.982g/L.     

不同抗性的向日葵品种接种锈菌后叶片中可溶性蛋白、可溶性总糖及叶绿素含量的变化

通过对两个不同抗性向日葵品种在苗期接种向日葵锈菌,测定了接种后不同时间叶片的可溶性总糖、可溶性蛋白及叶绿素含量的变化．研究结果表明：抗病品种的可溶性总糖比感病品种高;可溶性蛋白质含量、叶绿素b含量和类胡萝卜素含量的变化与向日葵抗病性有密切关系,而和叶绿素a含量的变化与抗病性没有直接关系．     

蛋白质空间结构的统计分析

利用数据挖掘中的数据分布拟合理论对生物科学领域中的蛋白质侧链空间结构进行统计分析.以世界上广泛使用的生物分子三维结构数据库PDB为基础,利用沈世镒教授提出的对多氨酸残基侧链碳原子间距离的统计分析方法,通过正交试验设计和信息论中的熵函数等相关知识,给出了不同位置、不同氨基酸残基种类对侧链结构的影响.     

CHOP及GRP78在复发性多形性胶质母细胞瘤患者表达显著增加

目的:研究CHOP及GRP78与复发性GBM的相关性。方法:采用Western blot检测CHOP及GRP78在初发及复发GBM组织中的表达;Real-time PCR检测GRP78在初发以及复发GBM组织中的表达。结果:CHOP及GRP78在初发GBM中表达上调,而在经过原发性肿瘤切除后接受放疗和替莫唑胺化疗的复发性GBM中增加尤为显著。结论:CHOP及GRP78在GBM发病机制中起重要作用,该分子有望成为GMB潜在的诊断及预后评估标志物。     

Mass spectrometry-based protein-protein interaction techniques and their applications in studies of DNA damage repair

Proteins are major functional units that are tightly connected to form complex and dynamic networks.These networks enable cells and organisms to operate properly and respond efficiently to environmental cues.Over the past decades,many biochemical methods have been developed to search for protein-binding partners in order to understand how protein networks are constructed and connected.At the same time,rapid development in proteomics and mass spectrometry(MS)techniques makes it possible to identify interacting proteins and build comprehensive protein-protein interaction networks.The resulting interactomes and networks have proven informative in the investigation of biological functions,such as in the field of DNA damage repair.In recent years,a number of proteins involved in DNA damage response and DNA repair pathways have been uncovered with MS-based protein-protein interaction studies.As the technologies for enriching associated proteins and MS become more sophisticated,the studies of protein-protein interactions are entering a new era.In this review,we summarize the strategies and recent developments for exploring protein-protein interaction.In addition,we discuss the application of these tools in the investigation of protein-protein interaction networks involved in DNA damage response and DNA repair.     

CRISPR/Cas: a Nobel Prize award-winning precise genome editing technology for gene therapy and crop improvement

Since it was first recognized in bacteria and archaea as a mechanism for innate viral immunity in the early 2010 s,clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-associated protein(Cas) has rapidly been developed into a robust, multifunctional genome editing tool with many uses. Following the discovery of the initial CRISPR/Cas-based system, the technology has been advanced to facilitate a multitude of different functions. These include development as a base editor, prime editor, epigenetic editor, and CRISPR interference(CRISPRi) and CRISPR activator(CRISPRa) gene regulators. It can also be used for chromatin and RNA targeting and imaging. Its applications have proved revolutionary across numerous biological fields, especially in biomedical and agricultural improvement. As a diagnostic tool, CRISPR has been developed to aid the detection and screening of both human and plant diseases, and has even been applied during the current coronavirus disease 2019(COVID-19) pandemic. CRISPR/Cas is also being trialed as a new form of gene therapy for treating various human diseases, including cancers, and has aided drug development. In terms of agricultural breeding, precise targeting of biological pathways via CRISPR/Cas has been key to regulating molecular biosynthesis and allowing modification of proteins, starch, oil, and other functional components for crop improvement. Adding to this, CRISPR/Cas has been shown capable of significantly enhancing both plant tolerance to environmental stresses and overall crop yield via the targeting of various agronomically important gene regulators. Looking to the future, increasing the efficiency and precision of CRISPR/Cas delivery systems and limiting off-target activity are two major challenges for wider application of the technology. This review provides an in-depth overview of current CRISPR development, including the advantages and disadvantages of the technology,recent applications, and future considerations.     

稻米的品质及其影响因素

自改革开放,尤其是中国加入世贸来,随着人民生活水平的提高以及稻米贸易对品质的要求,促使我国开始重视对稻米品质问题的研究.本文分别对近年来国内外关于稻米的品质及其影响因子研究进展情况作以简要论述.     

CD44v6mRNA和HSP70mRNA在胃癌中的表达及研究

目的:检测CD44v6mRNA和HSP70mRNA在胃癌组织中的表达,探讨CD44v6mRNA和HSP70mRNA在胃癌发生发展中的作用.方法:利用核酸原位杂交技术对39例胃癌组织进行检测.结果:CD44v6mRNA和HSP70mRNA在胃癌组织表达的阳性率都为61.54%(24/39),CD44v6mRNA和HSP70mRNA在高分化管状腺癌与低分化管状腺癌中的表达都有显著性差异(P＜0.05),但HSP70mRNA在胃癌组织的表达与性别、年龄、浸润深度及淋巴结有无转移都无关(P＞0.05),而CD44v6mRNA与淋巴结有无转移有关(P＜0.05).结论:CD44v6mRNA和HSP70mRNA在胃癌组织都有较高的表达,两者均可作为评估胃癌预后的指标.     

柴胡种子在萌发过程中氨基酸和蛋白质变化的初步研究

以柴胡种子为材料,经6-BA、60℃、KMnO4和对照4种方法进行萌发处理,测定了萌发处理过程中不同处理时间的柴胡种子中氨基酸和蛋白质含量的变化,初步探讨了在萌发过程中的生理生化变化规律．结果表明：氨基酸的变化总体呈现先升高再降低的趋势．在萌发0-6d之间氨基酸含量迅速升高,6d以后迅速降低,这种变化对柴胡种子的萌发是有利的．在不同处理下,柴胡种子在萌发期间,蛋白质的含量要经历一个迅速升高的过程,这种升高与氨基酸的变化一致．     

常量法和微量法测定蛋白质含量综合性实验设计

蛋白质含量测定是生物化学和分子生物学研究中最常用的分析方法之一。该文以Bradford法为基础,利用紫外分光光度计(常量法)和多功能酶标仪(微量法)分别进行蛋白质含量测定。在此基础上,总结了常量法和微量法在测定蛋白质含量中的异同点。结果表明:常量法适合样品数量少、体积大的体系;而微量法则可以大大提高测试效率,特别适宜样品数量多、体积少的体系表征。由于微量法在相同条件下可同时完成多个样品的测试,具有更高的测量准确性。两种方法在实验中的综合运用可大大提高实验效率,有助于学生掌握Bradford法测定蛋白质含量的原理,认识常量法和微量法测定蛋白质含量的共性及特性,提高学生对紫外分光光度计和多功能酶标仪工作原理及工作特点的认识,显著提升学生的实验能力和逻辑思维能力,为从事相关科研工作奠定基础。